U.S. patent number 10,288,105 [Application Number 15/897,579] was granted by the patent office on 2019-05-14 for bolt.
This patent grant is currently assigned to SANNOHASHI CORPORATION. The grantee listed for this patent is SANNOHASHI CORPORATION. Invention is credited to Hiroyuki Nakai, Fumitaka Saigo.
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United States Patent |
10,288,105 |
Saigo , et al. |
May 14, 2019 |
Bolt
Abstract
A bolt includes a head, and a shank connected to the head and
having a screw portion and a leading end portion. The leading end
portion of the shank includes a wall portion that defines a hole.
The wall portion includes: a deformation portion configured to be
plastically deformed by a torque from a fastening tool to be
inserted in the hole; and a space forming portion configured to
form a space between the space forming portion and the fastening
tool. The blot is configured such that a maximum torque applied to
the deformation portion in a process, in which a part of the
deformation portion is plastically deformed by the torque from the
fastening tool and is accommodated in the space and the fastening
tool is placed in an idle rotation state, is configured to be set
to be within a predetermined range.
Inventors: |
Saigo; Fumitaka (Saitama,
JP), Nakai; Hiroyuki (Smyrna, TN) |
Applicant: |
Name |
City |
State |
Country |
Type |
SANNOHASHI CORPORATION |
Yashio-shi, Saitama |
N/A |
JP |
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Assignee: |
SANNOHASHI CORPORATION
(Yashio-Shi, Saitama, JP)
|
Family
ID: |
58051576 |
Appl.
No.: |
15/897,579 |
Filed: |
February 15, 2018 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20180172054 A1 |
Jun 21, 2018 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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PCT/JP2015/073090 |
Aug 18, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16B
23/0007 (20130101); F16B 31/027 (20130101); F16B
31/021 (20130101); F16B 23/003 (20130101) |
Current International
Class: |
F16B
31/00 (20060101); F16B 31/02 (20060101); F16B
23/00 (20060101) |
Field of
Search: |
;411/4 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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09329118 |
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Dec 1997 |
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JP |
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2000110816 |
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Apr 2000 |
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JP |
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2000240627 |
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Sep 2000 |
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JP |
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2005530105 |
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Oct 2005 |
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JP |
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2006046475 |
|
Feb 2006 |
|
JP |
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2014156898 |
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Aug 2014 |
|
JP |
|
Other References
International Search Report corresponding to Application No.
PCT/JP2015/073090; dated Sep. 29, 2015. cited by applicant.
|
Primary Examiner: Estremsky; Gary W
Attorney, Agent or Firm: Cantor Colburn LLP
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation application under 35 U.S.C.
.sctn. 120 of PCT/JP2015/073090, filed Aug. 18, 2015, the entire
content of the PCT application is incorporated herein by reference.
Claims
What is claimed is:
1. A bolt, comprising: a head; and a shank connected to the head
and having a screw portion and a leading end portion, wherein the
leading end portion of the shank includes a wall portion that
defines a hole; the wall portion includes: a deformation portion
configured to be plastically deformed by a torque from a fastening
tool to be inserted in the hole; and a space forming portion
configured to form a space between the space forming portion and
the fastening tool; and the bolt is configured such that a maximum
torque applied to the deformation portion in a process, in which a
part of the deformation portion is plastically deformed by the
torque from the fastening tool and is accommodated in the space and
the fastening tool is placed in an idle rotation state, is
configured to be set to be within a predetermined range, wherein a
plurality of deformation portions are provided; and the plurality
of deformation portions are helically provided along an axial
direction of the shank.
2. The bolt according to claim 1, wherein the screw portion is
formed on an outer periphery of the leading end portion and on the
head side of the leading end portion in the shank.
3. A bolt, comprising: a head; and a shank connected to the head
and having a screw portion and a leading end portion, wherein the
leading end portion of the shank includes a wall portion that
defines a hole; the wall portion includes: a deformation portion
configured to be plastically deformed by a torque from a fastening
tool to be inserted in the hole; and a space forming portion
configured to form a space between the space forming portion and
the fastening tool; and the bolt is configured such that a maximum
torque applied to the deformation portion in a process, in which a
part of the deformation portion is plastically deformed by the
torque from the fastening tool and is accommodated in the space and
the fastening tool is placed in an idle rotation state, is
configured to be set to be within a predetermined range, wherein
the hole is tapered in a depth direction thereof.
4. The bolt according to claim 3, wherein the screw portion is
formed on an outer periphery of the leading end portion and on the
head side of the leading end portion in the shank.
5. A bolt, comprising: a head; and a shank connected to the head
and having a screw portion and a leading end portion, wherein the
leading end portion of the shank includes a wall portion that
defines a hole; the wall portion includes: a deformation portion
configured to be plastically deformed by a torque from a fastening
tool to be inserted in the hole; and a space forming portion
configured to form a space between the space forming portion and
the fastening tool; and the bolt is configured such that a maximum
torque applied to the deformation portion in a process, in which a
part of the deformation portion is plastically deformed by the
torque from the fastening tool and is accommodated in the space and
the fastening tool is placed in an idle rotation state, is
configured to be set to be within a predetermined range, wherein
the leading end portion is provided on an end portion of the screw
portion and a length of the leading end portion in a direction
orthogonal to an axis of the shank is shorter than a diameter of
the screw portion.
6. The bolt according to claim 5, further comprising a torque
transfer portion provided on an outer periphery of the leading end
portion and configured to receive a torque from a removal tool at
the time of removal.
7. A bolt, comprising: a head; a shank connected to the head and
having a screw portion; and a pintail provided on a leading end
side of the shank and having an outer peripheral portion, wherein
the outer peripheral portion includes: a deformation portion
configured to be plastically deformed by a torque from a fastening
tool; and a space forming portion configured to form a space
between the space forming portion and the fastening tool; and the
bolt is configured such that a maximum torque applied to the
deformation portion in a process, in which a part of the
deformation portion is plastically deformed by the torque from the
fastening tool and is accommodated in the space and the fastening
tool is placed in an idle rotation state, is configured to be set
to be within a predetermined range, wherein a plurality of
deformation portions are provided; and the plurality of deformation
portions are helically provided along an axial direction of the
shank.
8. A bolt, comprising: a head; a shank connected to the head and
having a screw portion; and a pintail provided on a leading end
side of the shank and having an outer peripheral portion, wherein
the outer peripheral portion includes: a deformation portion
configured to be plastically deformed by a torque from a fastening
tool; and a space forming portion configured to form a space
between the space forming portion and the fastening tool; and the
bolt is configured such that a maximum torque applied to the
deformation portion in a process, in which a part of the
deformation portion is plastically deformed by the torque from the
fastening tool and is accommodated in the space and the fastening
tool is placed in an idle rotation state, is configured to be set
to be within a predetermined range, wherein the pintail is tapered
toward a leading end thereof.
9. A bolt, comprising: a head; a shank connected to the head and
having a screw portion; and a pintail provided on a leading end
side of the shank and having an outer peripheral portion, wherein
the outer peripheral portion includes: a deformation portion
configured to be plastically deformed by a torque from a fastening
tool; and a space forming portion configured to form a space
between the space forming portion and the fastening tool; and the
bolt is configured such that a maximum torque applied to the
deformation portion in a process, in which a part of the
deformation portion is plastically deformed by the torque from the
fastening tool and is accommodated in the space and the fastening
tool is placed in an idle rotation state, is configured to be set
to be within a predetermined range, wherein an additional pintail
configured to receive a torque from a removal tool at the time of
removal is provided on a leading end of the pintail or between the
pintail and the leading end of the shank, the additional pintail
having a diameter different from that of the pintail.
10. A bolt, comprising: a head; a shank connected to the head and
having a screw portion; and a pintail provided on a leading end of
the shank and having an outer peripheral surface, wherein the outer
peripheral surface is provided with a plurality of protrusion
portions; and the bolt is configured such that a maximum torque
applied to the plurality of protrusion portions in a process, in
which the plurality of protrusion portions receive a torque from a
fastening tool and break from the outer peripheral surface and the
fastening tool is placed in an idle rotation state, is configured
to be set to be within a predetermined range, wherein the plurality
of protrusion portions are helically provided along an axial
direction of the shank.
Description
TECHNICAL FIELD
The present disclosure relates to a bolt that can be fastened from
one side thereof.
BACKGROUND
A bolt that can be fastened from one side thereof has been proposed
(for example, see Japanese Patent Application Publication No.
2000-110816).
In a bolt disclosed in Japanese Patent Application Publication No.
2000-110816, the bolt is fastened to a member to be fastened by a
desired fastening torque by rotating a nut and a pintail provided
on a leading end of a shank in directions opposite to each other by
a wrench and by breaking the pintail.
SUMMARY
However, in the bolt in Japanese Patent Application Publication No.
2000-110816, the pintail is provided on the shank. As a result, the
weight of the bolt increases and the cost increases. In addition,
the pintail breaks when the bolt is fastened, and hence the pintail
needs to be discarded and workability decreases when the bolt is
fastened.
An object of the present disclosure is to provide a bolt of which
weight and cost can be reduced.
A bolt in accordance with one or more embodiments includes a head,
and a shank connected to the head and having a screw portion and a
leading end portion. The leading end portion of the shank includes
a wall portion that defines a hole. The wall portion includes: a
deformation portion configured to be plastically deformed by a
torque from a fastening tool to be inserted in the hole; and a
space forming portion configured to form a space between the space
forming portion and the fastening tool. The bolt is configured such
that a maximum torque applied to the deformation portion in a
process, in which a part of the deformation portion is plastically
deformed by the torque from the fastening tool and is accommodated
in the space and the fastening tool is placed in an idle rotation
state, is configured to be set to be within a predetermined
range.
A bolt in accordance with one or more embodiments includes a head,
a shank connected to the head and having a screw portion, and a
pintail provided on a leading end side of the shank and having an
outer peripheral portion. The outer peripheral portion includes: a
deformation portion configured to be plastically deformed by a
torque from a fastening tool; and a space forming portion
configured to form a space between the space forming portion and
the fastening tool. The bolt is configured such that a maximum
torque applied to the deformation portion in a process, in which a
part of the deformation portion is plastically deformed by the
torque from the fastening tool and is accommodated in the space and
the fastening tool is placed in an idle rotation state, is
configured to be set to be within a predetermined range.
A bolt in accordance with one or more embodiments includes a head,
a shank connected to the head and having a screw portion, and a
pintail provided on a leading end of the shank and having an outer
peripheral surface. The outer peripheral surface is provided with a
plurality of protrusion portions. The bolt is configured such that
a maximum torque applied to the plurality of protrusion portions in
a process, in which the plurality of protrusion portions receive a
torque from a fastening tool and break from the outer peripheral
surface and the fastening tool is placed in an idle rotation state,
is configured to be set to be within a predetermined range.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawing:
FIG. 1 is a view illustrating a state in which a bolt and a nut are
tightened to a fastened member by a wrench according to a first
embodiment;
FIG. 2 is a cross-sectional view of a part near a leading end
portion of the bolt taken along a plane including an axis of the
shank;
FIG. 3 is a cross-sectional view of the bolt and an inner plug
taken along a line in FIG. 1;
FIG. 4 is a cross-sectional view of a bolt and an inner plug
according to the modification example 1-1 corresponding to the
cross-sectional view of the bolt and the inner plug taken along the
line in FIG. 1;
FIG. 5 is a cross-sectional view of a bolt and an inner plug
according to the modification example 1-2 corresponding to the
cross-sectional view of the bolt and the inner plug taken along the
line in FIG. 1;
FIG. 6 is a cross-sectional view of a bolt and an inner plug
according to the modification example 1-3 corresponding to the
cross-sectional view of the bolt and the inner plug taken along the
line in FIG.;
FIG. 7A is a cross-sectional view of a part near a leading end
portion of a bolt according to the modification example 1-4 taken
along a plane including the shaft of the shank;
FIG. 7B is a cross-sectional view of the bolt and an inner plug
according to the modification example 1-4 corresponding to the
cross-sectional view of the bolt and the inner plug taken along the
line in FIG. 1;
FIG. 8 is a cross-sectional view of a part near a leading end
portion of a bolt 61 according to the modification example 1-5
taken along a plane including the axis of the shank;
FIG. 9 is a cross-sectional view of a part near a leading end
portion of a bolt according to the modification example 1-6 taken
along a plane including the axis of the shank;
FIG. 10 is a cross-sectional view of a bolt and an inner plug of
the second embodiment corresponding to the cross-sectional view of
the bolt and the inner plug taken along the line in FIG. 1;
FIG. 11 is a view illustrating a state in which a bolt and the nut
are tightened to the fastened member by the wrench in the third
embodiment;
FIG. 12 is a cross-sectional view of the bolt and an inner socket
taken along the XII-XII line in FIG. 11;
FIG. 13 is a cross-sectional view of a bolt and an inner socket
according to the modification example 3-1 corresponding to the
cross-sectional view of the bolt and the inner socket taken along
the XII-XII line in FIG. 11;
FIG. 14 is a cross-sectional view of a bolt and an inner socket
according to the modification example 3-2 corresponding to the
cross-sectional view of the bolt and the inner socket taken along
the XII-XII line in FIG. 11;
FIG. 15A is an explanatory view of a pintail according to a bolt of
the modification example 3-3;
FIG. 15B is a cross-sectional view of the bolt and an inner socket
3S according to the modification example 3-3 corresponding to the
cross-sectional view of the bolt and the inner socket taken along
the XII-XII line in FIG. 11;
FIG. 16 is an explanatory view of a pintail and an inner socket of
a bolt according to the modification example 3-4;
FIG. 17A is an explanatory view of a pintail and the inner socket
of a bolt according to the modification example 3-5;
FIG. 17B is an end view of the pintail of the bolt according to the
modification example 3-5;
FIG. 18A is an explanatory view of a pintail and the inner socket
of a bolt according to the modification example 3-6;
FIG. 18B is an end view of the pintail of the bolt according to the
modification example 3-6;
FIG. 19A is an explanatory view of a pintail and an inner socket of
a bolt according to the fourth embodiment;
FIG. 19B is an end view of the pintail of the bolt according to the
fourth embodiment;
FIG. 20A is an explanatory view of a pintail and an inner socket of
a bolt according to the modification example 4-1;
FIG. 20B is an end view of the pintail of the bolt according to the
modification example 4-1;
FIG. 21A is an explanatory view of a pintail and an inner socket 5H
of a bolt according to the modification example 4-2;
FIG. 21B is an end view of the pintail of the bolt according to the
modification example 4-2;
FIG. 22A is a cross-sectional view of a part near a leading end
portion of a bolt according to the fifth embodiment taken along a
plane including the axis of the shank;
FIG. 22B is a cross-sectional view of the bolt and an inner plug
according to the fifth embodiment corresponding to the
cross-sectional view of the bolt and the inner socket taken along
the line in FIG. 1;
FIG. 23A is a cross-sectional view of a part near a leading end
portion of a bolt according to the modification example 5-1 taken
along a plane including the shaft of the shank;
FIG. 23B is a cross-sectional view of the bolt and an inner plug
according to the modification example 5-1 corresponding to the
cross-sectional view of the bolt and the inner socket taken along
the line in FIG. 1;
FIG. 24A is an explanatory view of a pintail of a bolt according to
the modification example 5-2;
FIG. 24B is a cross-sectional view of the bolt and an inner socket
according to the modification example 5-2 corresponding to the
cross-sectional view of the bolt and the inner socket aken along
the XII-XII line in FIG. 11;
FIG. 25A is an explanatory view of a pintail of a bolt according to
the modification example 5-3;
FIG. 25B is a cross-sectional view of the bolt and an inner socket
according to the modification example 5-3 corresponding to the
cross-sectional view of the bolt and the inner socket taken along
the XII-XII line in FIG. 11;
FIG. 26 is a side view of the pintail provided with a plurality of
end surface protrusion portions of the bolt according to the
modification example 5-2;
FIG. 27A is a cross-sectional view of a part near a leading end
portion of a bolt 401 according to the sixth embodiment taken along
a plane including the shaft of the shank;
FIG. 27B is a cross-sectional view of the bolt and an inner plug
according to the sixth embodiment corresponding to the
cross-sectional view of the bolt and the inner socket taken along
the line in FIG. 1;
FIG. 28 is a view illustrating a leading end portion of the bolt
according to the sixth embodiment in a state after fastening;
FIG. 29 is a cross-sectional view of a bolt and an inner plug
according to the modification example 6-1 corresponding to the
cross-sectional view of the bolt and the inner socket taken along
the line in FIG. 1;
FIG. 30 is a cross-sectional view of a bolt and an inner plug
according to the modification example 6-2 corresponding to the
cross-sectional view of the bolt and the inner socket taken along
the line in FIG. 1;
FIG. 31A is a view illustrating a leading end portion of a bolt
according to the modification example 6-3 in a state before
fastening;
FIG. 31B is a view illustrating the leading end portion of the bolt
according to the modification example 6-3 in a state after
fastening;
FIG. 32 is a view illustrating the leading end portion, in which an
outer peripheral surface of the leading end portion has a
dodecagonal shape, of the bolt according to the modification
example 1-6; and
FIG. 33 is a view illustrating the pintail provided with an
additional pintail of the bolt according to the third
embodiment.
DETAILED DESCRIPTION
A bolt according to some embodiments of the present disclosure is
described with reference to the drawings. FIG. 1 is a view
illustrating a state in which a bolt 1 and a nut 2 are tightened to
a fastened member 4 by a wrench 3 in a first embodiment. FIG. 2 is
a cross-sectional view of a part near a leading end portion 14 of
the bolt 1 taken along a plane including an axis of the shank 11.
FIG. 3 is a cross-sectional view of the bolt 1 and the inner plug
3A taken along a line in FIG. 1.
The bolt 1 is made of steel material and includes a cylindrical
shank 11 and a head 12 provided on one end of the shank 11 as
illustrated in FIG. 1. A male screw portion 13 is formed on an
outer periphery of the other end side of the shank 11. A hole 14a
is formed in the leading end portion 14 of the shank 11. The hole
14a is formed so that a cross-sectional shape thereof has a certain
shape along a depth direction (an axial direction of the shank 11)
as illustrated in FIG. 2.
As illustrated in FIG. 3, the hole 14a is formed as a dodecagonal
hole and an inner plug 3A having a hexagonal cross section is
inserted in the hole 14a when the bolt 1 is fastened. A wall
portion 15 forming the hole 14a in the leading end portion 14 has a
plurality of deformation portions 15A and a plurality of space
forming portions 15B. When the bolt 1 is fastened, each deformation
portion 15A receives a torque from a pressing portion 3C of the
inner plug 3A and is plastically deformed. Each space forming
portion 15B forms a space 14b between the space forming portion 15B
and the inner plug 3A inserted in the hole 14a. The wall portion 15
includes 12 deformation portions 15A and 12 space forming portions
15B and the inner plug 3A includes six pressing portions 3C, but
only one deformation portion 15A and one space forming portion 15B
are denoted by reference numbers in FIG. 3 for simplification of
illustration.
The wrench 3 includes the columnar inner plug 3A and a cylindrical
outer socket 3B. The inner plug 3A and the outer socket 3B is made
of a material having a hardness higher than the material of the
bolt 1.
Next, a method of tightening the bolt 1 according to this
embodiment to the fastened member 4 is described.
As illustrated in FIG. 1, in a state in which the bolt 1 is
inserted in the fastened member 4 and the nut 2 is screwed with the
male screw portion 13, the inner plug 3A is inserted in the hole
14a in the leading end portion 14 so that the outer socket 3B
surrounds the outer periphery of the nut 2.
The inner plug 3A and the outer socket 3B are rotated in directions
opposite to each other by a driving force from a driving source
(not shown) of the wrench 3. The inner plug 3A is rotated in a
rotation direction R as illustrated in FIG. 3. By this rotation,
each pressing portion 3C of the hexagonal inner plug 3A comes into
contact with the corresponding deformation portion 15A and
transfers a torque to the leading end portion 14 of the shank 11.
Then, the pressed deformation portion 15A is plastically deformed
and displaced by the torque of the inner plug 3A, the plastically
deformed part of each deformation portion 15A is accommodated in
the space 14b, and the inner plug 3A rotates idly.
In the bolt 1, the maximum torque applied to the plurality of
deformation portions 15A in the process in which a part of each
deformation portion 15A is plastically deformed by the torque from
the inner plug 3A and is accommodated in the corresponding space
14b and the inner plug 3A is placed in an idle rotation state is
set within a predetermined range. The predetermined range
corresponds to a desired fastening torque range. As a result, the
bolt 1 can be tightened to the fastened member 4 by a desired
fastening torque. The setting of the desired fastening torque for
the bolt 1 can be set as appropriate by adjusting the material of
the bolt 1, the depth of the hole 14a, the shape of the deformation
portion 15A, and the like.
According to the bolt 1 of this embodiment, the wall portion 15
forming the hole 14a in the leading end portion 14 of the shank 11
has the plurality of deformation portions 15A and the plurality of
space forming portions 15B that form the spaces 14b between the
plurality of space forming portions 15B and the inner plug 3A. A
part of each deformation portion 15A is plastically deformed by the
torque from the inner plug 3A and that displacement is accommodated
in the corresponding space 14b. From the abovementioned
configuration, each deformation portion 15A can be stably deformed
and the inner plug 3A can be idly rotated by applying a
predetermined torque to each deformation portion 15A. As a result,
the fastening torque can be stabilized when the bolt 1 is
fastened.
The bolt 1 of this embodiment has a structure without a pintail,
and hence the weight of the bolt 1 can be decreased and the cost
can be reduced. In the bolt 1 of this embodiment, no waste is
generated and workability can be enhanced.
Next, modification examples (modification examples 1-1 to 1-6) of
the bolt 1 according to the first embodiment 1 are described. The
same parts as those in the bolt 1 according to the first embodiment
1 are denoted by the same reference numbers and description thereof
is omitted. Only the different parts are described.
A bolt 21 according to the modification example 1-1 is described.
FIG. 4 is a cross-sectional view of the bolt 21 and an inner plug
3D according to the modification example 1-1 corresponding to the
cross-sectional view of the bolt 1 and the inner plug 3A taken
along the line in FIG. 1.
A hole 24a having a hexalobular shape is formed in a leading end
portion 24 of the shank 11 of the bolt 21. The inner plug 3D has a
hexalobular shape in correspondence to the hole 24a.
A wall portion 25 forming the hole 24a in the leading end portion
24 has six deformation portions 25A and six space forming portions
25B. When the bolt 1 is fastened, each deformation portion 25A
receives a torque from a pressing portion 3E of the inner plug 3D
and is plastically deformed. Each space forming portion 25B forms a
space 24b between the space forming portion 25B and the inner plug
3D inserted in the hole 24a. The wall portion 25 forming the hole
24a has six deformation portions 25A and six space forming portions
25B and the inner plug 3D has six pressing portions 3E, but only
one deformation portion 25A, one space forming portion 25B, and one
pressing portion 3E are denoted by reference numbers in FIG. 4 for
simplification of illustration.
The inner plug 3D is rotated in the rotation direction R as
illustrated in FIG. 4 by the driving force from the driving source
(not shown) of the wrench 3 (FIG. 1) also in this modification
example. By this rotation, each pressing portion 3E of the inner
plug 3D comes into contact with the corresponding deformation
portion 25A and transfers a torque to the leading end portion 24 of
the shank 11. Then, the pressed deformation portion 25A is
plastically deformed and displaced by the torque of the inner plug
3D, the plastically deformed part of each deformation portion 25A
is accommodated in the space 24b, and the inner plug 3D rotates
idly.
In the bolt 21, the maximum torque applied to the plurality of
deformation portions 25A in the process in which a part of each
deformation portion 25A is plastically deformed by the torque from
the inner plug 3D and is accommodated in the corresponding space
24b and the inner plug 3D is placed in an idle rotation state is
set to be within a predetermined range. As a result, the bolt 21
can be tightened to the fastened member by a desired fastening
torque.
Each deformation portion 25A can be stably deformed and the inner
plug 3D can be idly rotated by applying a predetermined torque to
each deformation portion 25A also in the bolt 21 having the
abovementioned configuration. As a result, the fastening torque can
be stabilized when the bolt 21 is fastened. The bolt 21 of this
modification example also achieves effects similar to those in the
bolt 1 of the first embodiment.
Next, a bolt 31 according to the modification example 1-2 is
described. FIG. 5 is a cross-sectional view of the bolt 31 and an
inner plug 3F according to the modification example 1-2
corresponding to the cross-sectional view of the bolt 1 and the
inner plug 3A taken along the line in FIG. 1.
A hole 34a is formed in a leading end portion 34 of the shank 11 of
the bolt 31. A wall portion 35 forming the hole 34a in the leading
end portion 34 has six inwardly projecting deformation portions 35A
and six space forming portions 35B. Each deformation portions 35A
are provided on the wall portion 35 at regular intervals in the
circumferential direction of the leading end portion 34. When the
bolt 31 is fastened, each deformation portion 35A receives a torque
from a pressing portion 3G of the inner plug 3F and is plastically
deformed. Each space forming portion 35B forms a space 34b between
the space forming portion 35B and the inner plug 3F inserted in the
hole 34a. The inner plug 3F has six sawtooth-like pressing portions
3G. The wall portion 35 forming the hole 34a has six deformation
portions 35A and six space forming portions 35B and the inner plug
3F has six pressing portions 3G, but only one deformation portion
35A, one space forming portion 35B, and one pressing portion 3G are
denoted by reference numbers in FIG. 5 for simplification of
illustration.
The inner plug 3F is rotated in the rotation direction R as
illustrated in FIG. 5 by the driving force from the driving source
(not shown) of the wrench 3 (FIG. 1) also in this modification
example. By this rotation, each pressing portion 3G of the inner
plug 3F comes into contact with the corresponding deformation
portion 35A and transfers a torque to the leading end portion 34 of
the shank 11. Then, the pressed deformation portion 35A is
plastically deformed and displaced by the torque of the inner plug
3F, the plastically deformed part of each deformation portion 35A
is accommodated in the space 34b, and the inner plug 3F rotates
idly.
In the bolt 31, the maximum torque applied to the plurality of
deformation portions 35A in the process in which a part of the
deformation portion 35A is plastically deformed by the torque from
the inner plug 3F and is accommodated in the space 34b and the
inner plug 3F is placed in an idle rotation state is set to be
within a predetermined range. As a result, the bolt 31 can be
tightened to the fastened member 4 by a desired fastening
torque.
Each deformation portion 35A can be stably deformed and the inner
plug 3F can be idly rotated by applying a predetermined torque to
each deformation portion 35A also in the bolt 31 having the
abovementioned configuration. As a result, the fastening torque can
be stabilized when the bolt 31 is fastened. The bolt 31 of this
modification example also achieves effects similar to those in the
bolt 1 of the embodiment.
Next, a bolt 41 according to the modification example 1-3 is
described. FIG. 6 is a cross-sectional view of the bolt 41 and an
inner plug 3H according to the modification example 1-3
corresponding to the cross-sectional view of the bolt 1 and the
inner plug 3A taken along the line in FIG. 1.
A hole 44a is formed in a leading end portion 44 of the shank 11 of
the bolt 41. The hole 44a has a cross-sectional shape that is a
shape formed by connecting four peak-trough shaped portions formed
of a pair of a peak portion and a trough portion. The inner plug 3H
has a substantially equilateral quadrangle shape.
A wall portion 45 forming the hole 44a in the leading end portion
44 has a deformation portion 45A corresponding to the peak portion
of the peak-trough shaped portion and a space forming portion 45B
corresponding to the trough portion of the peak-trough shaped
portion. When the bolt 41 is fastened, each deformation portion 45A
receives a torque from a pressing portion 31 of the inner plug 3H
and is plastically deformed. Each space forming portion 45B forms a
space 44b between the space forming portion 45B and the inner plug
3H inserted in the hole 44a. The wall portion 45 forming the hole
44a has four deformation portions 45A and four space forming
portions 45B and the inner plug 3H has four pressing portions 31,
but only one deformation portion 45A, one space forming portion
45B, and one pressing portion 31 are denoted by reference numbers
in FIG. 6 for simplification of illustration.
The inner plug 3H is rotated in the rotation direction R as
illustrated in FIG. 6 by the driving force from the driving source
(not shown) of the wrench 3 (FIG. 1) also in this modification
example. By this rotation, the pressing portions 31 of the inner
plug 3H comes into contact with all the deformation portions 45A
and transfers a torque to the leading end portion 44 of the shank
11. Then, each deformation portion 45A is plastically deformed and
displaced by the torque of the inner plug 3D, the plastically
deformed part of each deformation portion 45A is accommodated in
the space 44b, and the inner plug 3H rotates idly.
In the bolt 41, the maximum torque applied to the plurality of
deformation portions 45A in the process in which a part of each
deformation portion 45A is plastically deformed by the torque from
the inner plug 3H and is accommodated in the corresponding space
44b and the inner plug 3D is placed in an idle rotation state is
set to be within a predetermined range. As a result, the bolt 41
can be tightened to the fastened member 4 by a desired fastening
torque.
Each deformation portion 45A can be stably deformed and the inner
plug 3H can be idly rotated by applying a predetermined torque to
each deformation portion 45A also in the bolt 41 having the
abovementioned configuration. As a result, the fastening torque can
be stabilized when the bolt 41 is fastened. The bolt 41 of this
modification example also achieves effects similar to those in the
bolt 1 of the first embodiment.
Next, a bolt 51 according to the modification example 1-4 is
described. FIG. 7A is a cross-sectional view of a part near a
leading end portion 54 of the bolt 51 according to the modification
example 1-4 taken along a plane including the shaft of the shank 11
and FIG. 7B is a cross-sectional view of the bolt 51 and an inner
plug 3J according to the modification example 1-4 corresponding to
the cross-sectional view of the bolt 1 and the inner plug 3A taken
along the line in FIG. 1.
A hole 54a is formed in the leading end portion 54 of the shank 11
of the bolt 51 as illustrated in FIG. 7A and FIG. 7B. A wall
portion 55 forming the hole 54a in the leading end portion 54 has
eight inwardly projecting deformation portions 55A and eight space
forming portions 55B. Each deformation portion 55A is provided on
the wall portion 55 at regular intervals in the circumferential
direction of the leading end portion 54. The deformation portions
55A are provided helically along the axial direction of the shank
11. That is, the axis of the deformation portion 55A forming a
helical shape (helical axis) and the axis of the shank 11 are
coaxially arranged. When the bolt 51 is fastened, each deformation
portion 55A receives a torque from a pressing portion 3K of the
inner plug 3J and is plastically deformed. Each space forming
portion 55B forms a space 54b between the space forming portion 55B
and the inner plug 3J inserted in the hole 54a.
The inner plug 3J has eight sawtooth-like pressing portions 3K. The
pressing portions 3K are helically provided so as to correspond to
the helical deformation portions 55A. The wall portion 55 forming
the hole 54a has six deformation portions 55A and six space forming
portions 55B and the inner plug 3J has six pressing portions 3K,
but only one deformation portion 55A, one space forming portion
55B, and one pressing portion 3K are denoted by reference numbers
in FIG. 7A and FIG. 7B for simplification of illustration.
The inner plug 3J is rotated in the rotation direction R as
illustrated in FIG. 7B by the driving force from the driving source
(not shown) of the wrench 3 (FIG. 1) also in this modification
example. By this rotation, each pressing portion 3K of the inner
plug 3J comes into contact with the corresponding deformation
portion 55A and transfers a torque to the leading end portion 54 of
the shank 11. Then, each deformation portion 55A is plastically
deformed and displaced by the torque of the inner plug 3J, the
plastically deformed part of each deformation portion 55A is
accommodated in the space 54b, and the inner plug 3J rotates
idly.
In the bolt 51, the maximum torque applied to the plurality of
deformation portions 55A in the process in which a part of each
deformation portion 55A is plastically deformed by the torque from
the inner plug 3J and is accommodated in the space 54b and the
inner plug 3J is placed in an idle rotation state is set to be
within a predetermined range. As a result, the bolt 51 can be
tightened to the fastened member 4 by a desired fastening
torque.
The deformation portion 55A forms a helical shape and the pressing
portion 3K of the inner plug 3J also forms a helical shape, and
hence the inner plug 3J can be prevented from falling out of the
hole 54a when the bolt 51 is fastened. As a result, the depth of
the hole 54a can become shallower, and hence the length of bolt 51
can become shorter and the weight and the cost of the bolt 51 can
be reduced. The fastening torque can be changed by changing the
angle of the deformation portion 55A forming a helical shape.
Each deformation portion 55A can be stably deformed and the inner
plug 3J can be idly rotated by applying a predetermined torque to
each deformation portion 55A also in the bolt 51 having the
abovementioned configuration. As a result, the fastening torque can
be stabilized when the bolt 51 is fastened. The bolt 51 of this
modification example also achieves effects similar to those in the
bolt 1 of the first embodiment.
Next, a bolt 61 according to the modification example 1-5 is
described. FIG. 8 is a cross-sectional view of a part near a
leading end portion 64 of the bolt 61 according to the modification
example 1-5 taken along a plane including the axis of the shank
11.
A hole 64a is formed in the leading end portion 64 of the shank 11
of the bolt 61 as illustrated in FIG. 8. The hole 64a is tapered in
the depth direction. A wall portion forming the hole 64a in the
leading end portion 64 has the deformation portions and the space
forming portions in any of the first embodiment and the
modification examples 1-1 to 1-4. The leading end portion of an
inner plug 3L is tapered in correspondence to the shape of the hole
64a.
According to the bolt 61 of this modification example, it is
possible to easily pull out the inner plug 3L from the hole 64a
after the bolt 61 fastened. The bolt 61 of this modification
example achieves effects similar to those in the bolts in the first
embodiment 1 and the modification examples 1-1 to 1-4.
Next, a bolt 71 according to the modification example 1-6 is
described. FIG. 9 is a cross-sectional view of a part near a
leading end portion 74 of the bolt 71 according to the modification
example 1-6 taken along a plane including the axis of the shank
11.
As illustrated in FIG. 9, the leading end portion 74 is provided in
an end portion of the male screw portion 13 and the length of the
leading end portion 74 in the direction orthogonal to the axis of
the shank 11 is shorter than the diameter of the male screw portion
13. A wall portion forming a hole 74a in the leading end portion 74
has the deformation portions and the space forming portions in any
of the first embodiment and the modification examples 1-1 to
1-4.
According to the bolt 71 of this modification example, the male
screw portion 13 is short and hence the nut 2 can be easily
fastened. The bolt 71 of this modification example achieves effects
similar to those in the bolts in the first embodiment and the
modification examples 1-1 to 1-4. The hole 74a in the leading end
portion 74 may have a linear shape (substantially cylindrical
shape) along the axis of the shank 11 or may be tapered.
Next, a bolt 81 of a second embodiment of the present disclosure is
described with reference to FIG. 10.
FIG. 10 is a cross-sectional view of the bolt 81 and an inner plug
3H of the second embodiment corresponding to the cross-sectional
view of the bolt 1 and the inner plug 3A taken along the line in
FIG. 1. The same parts as those in the bolt 41 according to the
modification example 1-3 of the first embodiment 1 are denoted by
the same reference numbers and description thereof is omitted. Only
the different parts are described.
In the wall portion 45, a recessed portion 45c is formed on the
downstream side of each deformation portion 45A in the rotation
direction R of the inner plug 3H.
In this embodiment, the inner plug 3H is rotated in the rotation
direction R as illustrated in FIG. 10 by rotating the inner plug 3H
and the outer socket 3B (FIG. 1) in directions opposite to each
other by the driving force from the driving source (not shown) of
the wrench 3 (FIG. 1). By this rotation, each pressing portion 31
of the inner plug 3H comes into contact with the corresponding
deformation portion 45A and transfers a torque to the leading end
portion 44 of the shank 11. Then, each deformation portion 45A is
plastically deformed and displaced by the torque of the inner plug
3H, the plastically deformed part of each deformation portion 45A
is accommodated in the recessed portion 45c, and the inner plug 3H
rotates idly.
In the bolt 81, the maximum torque applied to the plurality of
deformation portions 45A in the process in which a part of each
deformation portion 45A is plastically deformed by the torque from
the inner plug 3H and is accommodated in the corresponding recessed
portion 45c and the inner plug 3H is placed in an idle rotation
state is set to be within a predetermined range. As a result, the
bolt 81 can be tightened to the fastened member 4 by a desired
fastening torque.
Each deformation portion 45A can be stably deformed and the inner
plug 3H can be idly rotated by applying a predetermined torque to
each deformation portion 45A also in the bolt 81 having the
abovementioned configuration. As a result, the fastening torque can
be stabilized when the bolt 81 is fastened. The bolt 81 of this
modification example achieves effects similar to those in the bolt
1 of the first embodiment. The hole 44a in the leading end portion
44 may have a linear shape (substantially cylindrical shape) along
the axis of the shank 11 or may be tapered. The leading end portion
44 may be provided in an end portion of the male screw portion 13
and the length of the leading end portion 44 in the direction
orthogonal to the axis of the shank 11 may be shorter than the
diameter of the male screw portion 13.
Next, a bolt 101 of a third embodiment of the present disclosure is
described with reference to FIG. 11 and FIG. 12. The same parts as
the bolt 1, the nut 2, and the wrench 3 described in the first
embodiment are denoted by the same reference numbers and
description thereof is omitted. Only the different parts are
described.
FIG. 11 is a view illustrating a state in which the bolt 101 and
the nut 2 are tightened to the fastened member 4 by the wrench 3 in
the third embodiment. FIG. 12 is a cross-sectional view of the bolt
101 and an inner socket 3M taken along the XII-XII line in FIG.
11.
In the bolt 101, a pintail 16 is provided on a leading end side of
the shank 11. The pintail 16 has a dodecagonal shape. When the bolt
101 is fastened, the pintail 16 is inserted in the cylindrical
inner socket 3M. An outer peripheral portion 17 of the pintail 16
has 12 deformation portions 17A and 12 space forming portions 17B.
When the bolt 101 is fastened, each deformation portion 17A
receives a torque from a pressing portion 3N of the inner socket 3M
and is plastically deformed. Each space forming portion 17B forms a
space 16a between the space forming portion 17B and the inner
socket 3M. The pintail 16 has 12 deformation portions 17A and 12
space forming portions 17B and the inner socket 3M has 12 pressing
portions 3N, but only one deformation portion 17A, one space
forming portion 17B, and one pressing portion 3N are denoted by
reference numbers in FIG. 12 for simplification of
illustration.
Next, a method of tightening the bolt 101 according to this
embodiment to the fastened member 4 is described.
As illustrated in FIG. 11, in a state in which the bolt 101 is
inserted in the fastened member 4 and the nut 2 is screwed with the
male screw portion 13, the inner socket 3M is inserted in the
pintail 16 and the nut 2 is inserted in the outer socket 3B.
The inner socket 3M and the outer socket 3B are rotated in
directions opposite to each other by the driving force from the
driving source (not shown) of the wrench 3. The inner socket 3M is
rotated in the rotation direction R as illustrated in FIG. 12. By
this rotation, each pressing portion 3N of the inner socket 3M
comes into contact with the corresponding deformation portion 17A
and transfers a torque to the pintail 16. Then, each deformation
portion 17A is plastically deformed and displaced by the torque of
the inner socket 3M, the plastically deformed part of each
deformation portion 17A is accommodated in the space 16a, and the
inner socket 3M rotates idly.
In the bolt 101, the maximum torque applied to the plurality of
deformation portions 17A in the process in which a part of each
deformation portion 17A is plastically deformed by the torque from
the inner socket 3M and is accommodated in the corresponding space
16a and the inner socket 3M is placed in an idle rotation state is
set to be within a predetermined range. The predetermined range
corresponds to a desired fastening torque range. As a result, the
bolt 101 can be tightened to the fastened member 4 by a desired
fastening torque. In the bolt 101, the setting of the desired
fastening torque can be set as appropriate by adjusting the
material of the bolt 101, the length of the pintail 16, the shape
of the deformation portion 17A, and the like.
According to the bolt 101 of this embodiment, the outer peripheral
portion 17 of the pintail 16 has the plurality of deformation
portions 17A and the plurality of space forming portions 17B that
form the spaces 16a between the plurality of space forming portions
17B and the inner socket 3M. A part of each deformation portion 17A
is plastically deformed by the torque from the inner socket 3M and
that displacement is accommodated in the corresponding space 16a.
From the abovementioned configuration, each deformation portion 17A
can be stably deformed and the inner socket 3M can be idly rotated
by applying a predetermined torque to each deformation portion 17A.
As a result, the fastening torque can be stabilized when the bolt
101 is fastened.
The bolt 101 of this embodiment has a structure in which the
pintail 16 does not fall out, and hence no waste is generated and
workability can be enhanced.
Next, modification examples (modification examples 3-1 to 3-6) of
the bolt 101 according to the third embodiment are described. The
same parts as those in the bolt 101 according to the third
embodiment are denoted by the same reference numbers and
description thereof is omitted. Only the different parts are
described.
A bolt 111 according to the modification example 3-1 is described.
FIG. 13 is a cross-sectional view of the bolt 111 and an inner
socket 30 according to the modification example 3-1 corresponding
to the cross-sectional view of the bolt 101 and the inner socket 3M
taken along the XII-XII line in FIG. 11.
A pintail 26 of the bolt 111 has a hexalobular shape. The inner
socket 30 has a substantially hexalobular shape in correspondence
to the pintail 26.
An outer peripheral portion 27 of the pintail 26 has six
deformation portions 27A and six space forming portions 27B. When
the bolt 111 is fastened, each deformation portion 27A receives a
torque from a pressing portion 3P of the inner socket 30 and is
plastically deformed. Each space forming portion 27B forms a space
26a between the space forming portion 27B and the inner socket 30.
The outer peripheral portion 27 has six deformation portions 27A
and six space forming portions 27B and the inner socket 30 has six
pressing portions 3P, but only one deformation portion 27A, one
space forming portion 27B, and one pressing portion 3P are denoted
by reference numbers in FIG. 13 for simplification of
illustration.
The inner socket 30 is rotated in the rotation direction R as
illustrated in FIG. 13 by the driving force from the driving source
(not shown) of the wrench 3 (FIG. 1) also in this modification
example. By this rotation, the pressing portions 3P of the inner
socket 30 comes into contact with all the deformation portions 27A
and transfers a torque to the pintail 26. Then, each deformation
portion 27A is plastically deformed and displaced by the torque of
the inner socket 30, the plastically deformed part of each
deformation portion 27A is accommodated in the space 26a, and the
inner socket 30 rotates idly.
In the bolt 111, the maximum torque applied to the plurality of
deformation portions 27A in the process in which a part of each
deformation portion 27A is plastically deformed by the torque from
the inner socket 30 and is accommodated in the corresponding space
16a and the inner socket 30 is placed in an idle rotation state is
set to be within a predetermined range. As a result, the bolt 111
can be tightened to the fastened member 4 by a desired fastening
torque.
Each deformation portion 27A can be stably deformed and the inner
socket 30 can be idly rotated by applying a predetermined torque to
each deformation portion 27A also in the bolt 111 having the
abovementioned configuration. As a result, the fastening torque can
be stabilized when the bolt 111 is fastened. The bolt 111 of this
modification example also achieves effects similar to those in the
bolt 101 of the third embodiment.
Next, a bolt 121 according to the modification example 3-2 is
described. FIG. 14 is a cross-sectional view of the bolt 121 and an
inner socket 3Q according to the modification example 3-2
corresponding to the cross-sectional view of the bolt 101 and the
inner socket 3M taken along the XII-XII line in FIG. 11.
A pintail 36 of the bolt 121 has a cylindrical shape. An outer
peripheral portion 37 of the pintail 36 has six outwardly
projecting deformation portions 37A and six space forming portions
37B. The deformation portions 37A are provided on the outer
peripheral portion 37 at regular intervals in the circumferential
direction thereof. When the bolt 121 is fastened, each deformation
portion 37A receives a torque from a pressing portion 3R of the
inner socket 3Q and is plastically deformed. Each space forming
portion 37B forms a space 36a between the space forming portion 37B
and the inner socket 3Q. The inner socket 3Q has six pressing
portions 3R. The outer peripheral portion 37 has six deformation
portions 37A and six space forming portions 37B and the inner
socket 3Q has six pressing portions 3R, but only one deformation
portion 37A, one space forming portion 37B, and one pressing
portion 3R are denoted by reference numbers in FIG. 14 for
simplification of illustration.
The inner socket 3Q is rotated in the rotation direction R as
illustrated in FIG. 14 by the driving force from the driving source
(not shown) of the wrench 3 (FIG. 1) also in this modification
example. By this rotation, each pressing portion 3R of the inner
socket 3Q comes into contact with the corresponding deformation
portion 37A and transfers a torque to the leading end portion 34 of
the shank 11. Then, each deformation portion 37A is plastically
deformed and displaced by the torque of the inner socket 3Q, the
plastically deformed part of each deformation portion 37A is
accommodated in the space 36a, and the inner socket 3Q rotates
idly.
In the bolt 121, the maximum torque applied to the plurality of
deformation portions 37A in the process in which a part of the
deformation portion 37A is plastically deformed by the torque from
the inner socket 3Q and is accommodated in the space 36a and the
inner socket 3Q is placed in an idle rotation state is set to be
within a predetermined range. As a result, the bolt 121 can be
tightened to the fastened member by a desired fastening torque.
The deformation portion 37A can be stably deformed and the inner
socket 3Q can be idly rotated by applying a predetermined torque to
the deformation portion 37A also in the bolt 121 having the
abovementioned configuration. As a result, the fastening torque can
be stabilized when the bolt 121 is fastened. The bolt 121 of this
modification example also achieves other effects similar to those
in the bolt 101 of the third embodiment.
Next, a bolt 131 according to the modification example 3-3 is
described. FIG. 15A is an explanatory view of a pintail 46
according to the bolt 131 of the modification example 3-3 and FIG.
15B is a cross-sectional view of the bolt 131 and an inner socket
3S according to the modification example 3-3 corresponding to the
cross-sectional view of the bolt 101 and the inner socket 3M taken
along the XII-XII line in FIG. 11.
An outer peripheral portion 47 of the pintail 46 of the bolt 131
has eight outwardly projecting deformation portions 47A and eight
space forming portions 47B as illustrated in FIG. 15A and FIG. 15B.
The deformation portions 47A are provided on the outer peripheral
portion 47 at regular intervals in the circumferential direction
thereof. The deformation portions 47A are helically provided along
the axial direction of the shank 11. That is, the axis (helical
axis) of the deformation portion 47A forming a helical shape and
the axis of the shank 11 are coaxially arranged. When the bolt 131
is fastened, the deformation portion 47A receives a torque from a
pressing portion 3T of the inner socket 3S and is plastically
deformed. Each space forming portion 47B forms a space 46a between
the space forming portion 47B the inner socket 3S.
The inner socket 3S has eight pressing portions 3T. The pressing
portions 3T are helically provided so as to correspond to the
helical deformation portions 47A. The outer peripheral portion 47
has eight deformation portions 47A and eight space forming portions
47B and the inner socket 3S has eight pressing portions 3T, but
only one deformation portion 47A, one space forming portion 47B,
and one pressing portion 3T are denoted by reference numbers in
FIG. 15A and FIG. 15B for simplification of illustration.
The inner socket 3S is rotated in the rotation direction R as
illustrated in FIG. 15B by the driving force from the driving
source (not shown) of the wrench 3 (FIG. 1) also in this
modification example. By this rotation, each pressing portion 3T of
the inner socket 3S comes into contact with the corresponding
deformation portion 47A and transfers a torque to the leading end
portion 54 of the shank 11. Then, each deformation portion 47A is
plastically deformed and displaced by the torque of the inner
socket 3S, the plastically deformed part of each deformation
portion 47A is accommodated in the space 46a, and the inner socket
3S rotates idly.
In the bolt 131, the maximum torque applied to the plurality of
deformation portions 47A in the process in which a part of each
deformation portion 47A is plastically deformed by the torque from
the inner socket 3S and is accommodated in the space 46a and the
inner socket 3S is placed in an idle rotation state is set to be
within a predetermined range. As a result, the bolt 131 can be
tightened to the fastened member 4 by a desired fastening
torque.
Each deformation portion 47A forms a helical shape and each
pressing portion 3T of the inner socket 3S also forms a helical
shape, and hence the inner socket 3S can be prevented from falling
out of the pintail 46 when the bolt 131 is fastened. As a result,
the length of the pintail 46 can become shorter, and hence the
length of the bolt 131 can become shorter and the weight and the
cost of the bolt 131 can be reduced. The fastening torque can be
changed by changing the angle of the deformation portion 47A
forming a helical shape.
Next, a bolt 141 according to the modification example 3-4 is
described. FIG. 16 is an explanatory view of a pintail 56 and an
inner socket 3U of the bolt 141 according to the modification
example 3-4.
The pintail 56 of the bolt 141 is tapered toward the leading end as
illustrated in FIG. 16. An outer peripheral portion of the pintail
56 has the deformation portions and the space forming portions in
any of the third embodiment and the modification examples 3-1 to
3-3. An inner peripheral surface of the inner socket 3U is tapered
in correspondence to the pintail 56.
According to the bolt 141 of this modification example, it is
possible to easily remove the inner socket 3U from the pintail
after the bolt 141 fastened. The bolt 141 of this modification
example achieves effects similar to those in the bolts in the third
embodiment and modification examples 3-1 to 3-3.
Next, a bolt 151 according to the modification example 3-5 is
described. FIG. 17A is an explanatory view of a pintail 66 and the
inner socket 3M of the bolt 151 according to the modification
example 3-5 and FIG. 17B is an end view of the pintail 66.
As illustrated in FIG. 17A and FIG. 17B, the pintail 66 of the bolt
151 has a plurality of projection portions 66D (Only one projection
portion 66D is denoted by a reference number in FIG. 17A and FIG.
17B.) on an end surface 66C thereof in addition to the
configuration in the pintail 16 of the bolt 101 of the third
embodiment.
When the bolt 151 is fastened, the inner socket 3M is rotated in
the rotation direction R, the pressing portion 3N of the inner
socket 3M comes into contact with the deformation portion 17A, and
a pressing projection 3V provided on the inner socket 3M comes into
contact with each projection portion 66D and transfers a torque to
the pintail 66. Then, the projection portion 66D is plastically
deformed by the torque from the inner socket 3M.
According to the bolt 151 of this modification example, not only
the outer peripheral portion 17 of the pintail 66 but also the end
surface 66C receives the torque of the inner socket 3M, and hence
the length of the pintail 66 can become shorter and the length of
the bolt 151 can become shorter. As a result, the weight and the
cost of the bolt 151 can be reduced.
The outer peripheral portion of the pintail 66 may be the
deformation portion and the space forming portion in any of the
modification examples 3-1 to 3-3 and may be tapered. The bolt 151
of this modification example achieves effects similar to those in
the bolts in the third embodiment and the modification example 3-1
to 3-4.
Next, a bolt 161 according to the modification example 3-6 is
described. FIG. 18A is an explanatory view of a pintail 76 and the
inner socket 3M of the bolt 161 according to the modification
example 3-6 and FIG. 18B is an end view of the pintail 76 of the
bolt 161.
As illustrated in FIG. 18A and FIG. 18B, the pintail 76 of the bolt
161 has an annular recessed portion 76d formed in an end surface
76C thereof in addition to the configuration in the pintail 16 of
the bolt 101 of the third embodiment. The pintail 76 has four
pressed portions 76E (Only one pressed portion 76E is denoted by a
reference number in FIG. 18A and FIG. 18B.) that narrows the width
of the recessed portion 76d. The width of the recessed portion 76d
in the pressed portion 76E is smaller than the diameter of a
columnar projection 3W provided in the inner socket 30.
When the bolt 161 is fastened, the columnar projection 3W is
inserted in the recessed portion 76d, the inner socket 3M is
rotated in the rotation direction R, each pressing portion 3N comes
into contact with the corresponding deformation portion 17A, and
each columnar projection 3W comes into contact with the
corresponding pressed portion 76E and transfers a torque to the
pintail 76. Then, each pressed portion 76E is plastically deformed
by the torque from the inner socket 3M and each cylindrical
projection 3W passes through the pressed portion 76E.
According to the bolt 161 of this modification example, not only
the outer peripheral portion 17 of the pintail 76 but also the end
surface 76C receives the torque of the inner socket 3M, and hence
the length of the pintail 76 can become shorter and the length of
the bolt 161 can become shorter. As a result, the weight and the
cost of the bolt 161 can be reduced.
The outer peripheral portion of the pintail 76 may be the
deformation portion and the space forming portion in any of the
modification examples 3-1 to 3-3 and may be tapered. The bolt 161
of this modification example achieves effects similar to those in
the bolts in the third embodiment and the modification example 3-1
to 3-4.
Next, a bolt 201 of a fourth embodiment of the present disclosure
is described with reference to FIG. 19A and FIG. 19B. The same
parts as those in the bolt 101 described in the third embodiment
are denoted by the same reference numbers and description thereof
is omitted. Only the different parts are described.
FIG. 19A is an explanatory view of a pintail 18 and an inner socket
5A of the bolt 201 according to the fourth embodiment and FIG. 19B
is an end view of the pintail 18 of the bolt 201.
In the bolt 201, the pintail 18 is provided on the leading end side
of the shank 11 and an annular groove portion 19 is formed between
the shank 11 and the pintail 18. The shape of the cross section of
the pintail 18 orthogonal to the axis of the shank 11 is a
dodecagon (non-circular shape) and the pintail 18 has 12 pressed
portions 18A on an outer peripheral portion thereof. Eight
projection portions (engagement portions) 18C are provided on an
end surface 18B of the pintail 18. The inner socket 5A has 12
pressing portions 5B on an inner periphery thereof and eight
pressing projections 5C are provided on a bottom thereof. Although
12 pressed portions 18A, 12 projection portions 18C, 12 pressing
portions 5B, and 12 pressing projections 5C are provided, only one
pressed portion 18A, one projection portion 18C, one pressing
portion 5B, and one pressing projection 5C are denoted by reference
numbers in FIG. 19A and FIG. 19B for simplification of
illustration.
In this embodiment, the inner socket 5A is rotated in the rotation
direction R as illustrated in FIG. 19B by rotating the inner socket
5A and the outer socket 3B (FIG. 1) in directions opposite to each
other by the driving force from the driving source (not shown) of
the wrench 3 (FIG. 1). By this rotation, the pressing portion 5B
and the pressing projection 5C of the inner socket 5A come into
contact with all the pressed portions 18A and projection portions
18C and transfer a torque to the pintail 18. Then, the groove
portion 19 breaks by the torque of the inner socket 5A, the pintail
18 is removed from the shank 11, and the inner socket 5A rotates
idly.
In the bolt 201, the maximum torque applied to the groove portion
19 in the process in which each pressed portion 18A and each
projection portion 18C of the pintail 18 receive the torque from
the inner socket 5A, the groove portion 19 breaks, and the pintail
18 is placed in a state of being removed from the shank 11 is set
to be within a predetermined range. The predetermined range
corresponds to a desired fastening torque range. As a result, the
bolt 201 can be tightened to the fastened member 4 by a desired
fastening torque. The setting of the desired fastening torque in
the bolt 201 can be set as appropriate by adjusting the material of
the bolt 201, the cross-sectional shape of the pintail 18, the
shape of the projection portion 18C, and the like.
According to the bolt 201 having the abovementioned configuration,
the torque is transferred to the pintail 18 by the plurality of
projection portions 18C of the end surface 18B in addition to the
plurality of pressed portions 18A of the outer peripheral portion
of the pintail 18, and hence the length of the pintail 18 can
become shorter. As a result, the waste and the cost can be
reduced.
Next, modification examples (modification examples 4-1 to 4-2) of
the bolt 201 according to the fourth embodiment are described. The
same parts as those in the bolt 201 according to the fourth
embodiment are denoted by the same reference numbers and
description thereof is omitted. Only the different parts are
described.
A bolt 211 according to the modification example 4-1 is described.
FIG. 20A is an explanatory view of a pintail 28 and an inner socket
5D of the bolt 211 according to the modification example 4-1 and
FIG. 20B is an end view of the pintail 28 of the bolt 211.
In the bolt 211, the pintail 28 is provided on the leading end side
of the shank 11 and the annular groove portion 19 is formed between
the shank 11 and the pintail 28. The shape of the cross section of
the pintail 28 orthogonal to the axis of the shank 11 is a
dodecagon (non-circular shape) and the pintail 28 has 12 first
pressed portions 28A on an outer peripheral portion. A hole 28c,
which opens on the end surface 28B and of which cross section
orthogonal to the axis of the shank 11 is a hexagon (non-circular
shape), is formed in the pintail 28. The part forming each corner
of the hexagonal hole 28c of the pintail 28 serves as a second
pressed portion 28D. The inner socket 5D has 12 first pressing
portions 5E on an inner periphery thereof and has a hexagonal plug
5F provided in the inside thereof. The plug 5F has six second
pressing portions 5G and is inserted in the hole 28c when the bolt
211 is fastened.
The plurality of the first pressed portions 28A, the plurality of
second pressed portions 28D, the plurality of first pressing
portions 5E, and the plurality of second pressing portions 5G are
provided, but only one first pressed portion 28A, one second
pressed portion 28D, one first pressing portion 5E, and one second
pressing portion 5G are denoted by reference numbers in FIG. 20A
and FIG. 20B for simplification of illustration.
The inner socket 5D is rotated in the rotation direction R as
illustrated in FIG. 20B by the driving force from the driving
source (not shown) of the wrench 3 (FIG. 1) also in this
modification example. By this rotation, each first pressing portion
5E and each second pressing portion 5G of the inner socket 5D come
into contact with the corresponding first pressed portion 28A and
the corresponding second pressed portion 28D and transfer a torque
to the pintail 28. Then, the groove portion 19 breaks by the torque
of the inner socket 5D, the pintail 28 is removed from the shank
11, and the inner socket 5D rotates idly.
In the bolt 211, the maximum torque applied to the groove portion
19 in the process in which each first pressed portion 28A and each
second pressed portion 28D of the pintail 28 receive the torque
from the inner socket 5D, the groove portion 19 breaks, and the
pintail 28 is placed in a state of being removed from the shank 11
is set to be within a predetermined range. The predetermined range
corresponds to a desired fastening torque range. As a result, the
bolt 211 can be tightened to the fastened member 4 by a desired
fastening torque.
According to the bolt 211 having the abovementioned configuration,
the torque is transferred to the pintail 28 by the plurality of
second pressed portions 28D in addition to the plurality of first
pressed portions 28A of the outer peripheral portion of the pintail
28 and hence the length of the pintail 28 can become shorter. As a
result, the waste and the cost can be reduced.
A bolt 221 according to the modification example 4-2 is described.
FIG. 21A is an explanatory view of a pintail 38 and an inner socket
5H of the bolt 221 according to the modification example 4-2 and
FIG. 21B is an end view of the pintail 38 of the bolt 221.
In the bolt 221, the pintail 38 is provided on the leading end side
of the shank 11 and the annular groove portion 19 is formed between
the shank 11 and the pintail 38. The shape of the cross section of
the pintail 38 orthogonal to the axis of the shank 11 is a
dodecagon (non-circular shape) and the pintail 38 has 12 first
pressed portions 38A on an outer peripheral portion. A hole 38c,
which opens on an end surface 38B and of which cross section
orthogonal to the axis of the shank 11 is a hexagon (non-circular
shape), is formed in the pintail 38. The portion forming each
corner of the hexagonal hole 38c of the pintail 38 serves as a
second pressed portion 38D. Eight projection portions (engagement
portions) 38E are provided on the end surface 38B of the pintail
38.
The inner socket 5H has 12 first pressing portions 51 on an inner
periphery thereof and has a hexagonal plug 5J and eight pressing
projections 5K provided in the inside thereof. The plug 5J has six
second pressing portions 5L and is inserted in the hole 38c when
the bolt 221 is fastened.
The plurality of the first pressed portions 38A, the plurality of
second pressed portions 38D, the plurality of projection portions
38E, the plurality of first pressing portions 5E, the plurality of
second pressing portions 5L, and the plurality of pressing
projections 5K are provided, but only one first pressed portion
38A, one second pressed portion 38D, one projection portion 38E,
one first pressing portion 5E, one second pressing portion 5L, and
one pressing projection 5K are denoted by reference numbers in FIG.
21A and FIG. 21B for simplification of illustration.
The inner socket 5H is rotated in the rotation direction R as
illustrated in FIG. 21B by the driving force from the driving
source (not shown) of the wrench 3 (FIG. 1) also in this
modification example. By this rotation, each first pressing portion
5E, each second pressing portion 5L, and each pressing projection
5K of the inner socket 5H come into contact with the corresponding
first pressed portion 38A, the corresponding second pressed portion
38D, and the corresponding projection portion 38E and transfer a
torque to the pintail 38. Then, the groove portion 19 breaks by the
torque of the inner socket 5H, the pintail 38 is removed from the
shank 11, and the inner socket 5H rotates idly.
In the bolt 221, the maximum torque applied to the groove portion
19 in the process in which each first pressed portion 38A, each
second pressed portion 38D, and each projection portion 38E of the
pintail 38 receive the torque from the inner socket 5H, the groove
portion 19 breaks, and the pintail 38 is placed in a state of being
removed from the shank 11 is set to be within a predetermined
range. The predetermined range corresponds to a desired fastening
torque range. As a result, the bolt 221 can be tightened to the
fastened member 4 by a desired fastening torque.
According to the bolt 221 having the abovementioned configuration,
the torque is transferred to the pintail 38 by the plurality of
second pressed portions 38D and the plurality of projection
portions 38E of the end surface 38B in addition to the plurality of
first pressed portions 38A of an outer peripheral portion of the
pintail 38, and hence the length of the pintail 38 can become
shorter. As a result, the waste and the cost can be reduced.
In the fourth embodiment and the modification examples thereof, the
shapes of the cross sections of the pintails 18, 28, and 38
orthogonal to the axis of the shank 11 have dodecagonal shapes, but
may have a hexagonal or a hexalobular shape. In the same manner,
the shapes of the cross sections of the holes 28c and 38c formed in
the pintails 28 and 38 orthogonal to the axis of the shank 11 are
hexagons, but may be dodecagonal hole shapes or hexalobular
shapes.
Next, a bolt 301 of a fifth embodiment of the present disclosure is
described with reference to FIG. 22A and FIG. 22B. The same parts
as those described in the bolt 1 of the first embodiment 1 are
denoted by the same reference numbers and description thereof is
omitted. Only the different parts are described.
FIG. 22A is a cross-sectional view of a part near a leading end
portion of the bolt 301 according to the fifth embodiment taken
along a plane including the axis of the shank 11 and FIG. 22B is a
cross-sectional view of the bolt 301 and an inner plug 6A according
to the fifth embodiment corresponding to the cross-sectional view
of the bolt 1 and the inner socket 3A taken along the line in FIG.
1.
A hole 22a is formed in a leading end portion 22 of the shank 11 of
the bolt 301. Eight inwardly projecting protrusion portions 22C are
provided on a wall surface 22b of the hole 22a. The protrusion
portions 22C are provided on the wall surface 22b at regular
intervals in the circumferential direction of the leading end
portion 22. When the bolt 301 is fastened, each protrusion portion
22C receives a torque from a pressing portion 6B of the inner plug
6A and breaks from the wall surface 22b. Eight protrusion portions
22C are provided on the wall surface 22b of the hole 22a and the
inner plug 6A has eight pressing portions 6B, but only one
protrusion portion 22C and one pressing portion 6B are denoted by
reference numbers in FIG. 22A and FIG. 22B for simplification of
illustration.
In this embodiment, the inner plug 6A is rotated in the rotation
direction R as illustrated in FIG. 22B by rotating the inner plug
6A and the outer socket 3B (FIG. 1) in directions opposite to each
other by the driving force from the driving source (not shown) of
the wrench 3 (FIG. 1). By this rotation, each pressing portion 6B
of the inner plug 6A comes into contact with the corresponding
protrusion portion 22C and transfers a torque to the leading end
portion 34 of the shank 11. Then, each protrusion portion 22C
breaks from the wall surface 22b by the torque of the inner plug 6A
and the inner plug 6A rotates idly.
In the bolt 301, the maximum torque applied to the plurality of
protrusion portions 22C in the process in which the plurality of
protrusion portions 22C receives a torque from the inner plug 6A
and breaks from the wall surface 22b and the inner plug 6A is
placed in an idle rotation state is set to be within a
predetermined range. The predetermined range corresponds to a
desired fastening torque range. As a result, the bolt 301 can be
tightened to the fastened member 4 by a desired fastening torque.
The setting of the desired fastening torque can be set as
appropriate by adjusting the material of the bolt 301, the size of
the protrusion portion 22C, and the like.
According to the bolt 301 of this embodiment, the amount of waste
can be smaller than that in the case in which the desired fastening
torque is acquired by breaking the pintail. Thus, risks caused by
falling wastes can be reduced when the bolt 301 is used at a high
place. The bolt 301 has a structure without a pintail, and hence
the weight of the bolt 301 can be decreased and the cost can be
reduced.
Next, modification examples (modification examples 5-1 to 5-3) of
the bolt 301 according to the fifth embodiment are described. The
same parts as those in the bolt 301 according to the fifth
embodiment are denoted by the same reference numbers and
description thereof is omitted. Only the different parts are
described.
A bolt 311 according to the modification example 5-1 is described.
FIG. 23A is a cross-sectional view of a part near a leading end
portion 32 of the bolt 311 according to the modification example
5-1 taken along a plane including the shaft of the shank 11 and
FIG. 23B is a cross-sectional view of the bolt 311 and an inner
plug 6C according to the modification example 5-1 corresponding to
the cross-sectional view of the bolt 1 and the inner socket 3A
taken along the line in FIG. 1.
A hole 32a is formed in the leading end portion 32 of the shank 11
of the bolt 311. Eight inwardly projecting protrusion portions 32C
are provided on a wall surface 32b of the hole 32a. The protrusion
portions 32C are provided on the wall surface 32b at regular
intervals in the circumferential direction of the leading end
portion 32. The protrusion portions 32C are helically provided
along the axial direction of the shank 11. That is, the axis
(helical axis) of the protrusion portion 32C forming a helical
shape and the axis of the shank 11 are coaxially arranged. When the
bolt 311 is fastened, each protrusion portion 32C receives a torque
from a pressing portion 6D of the inner plug 6C and breaks from the
wall surface 32b.
The inner plug 6C has eight pressing portions 6D. The pressing
portions 6D are helically provided so as to correspond to the
helical protrusion portions 32C. Eight protrusion portions 32C are
provided on the wall surface 32b of the hole 32a and the inner plug
6C has eight pressing portions 6D, but only one protrusion portion
32C and one pressing portion 6B are denoted by reference numbers in
FIG. 23A and FIG. 23B for simplification of illustration.
The inner plug 6C is rotated in the rotation direction R as
illustrated in FIG. 23B by the driving force from the driving
source (not shown) of the wrench 3 (FIG. 1) also in this
modification example. By this rotation, each pressing portion 6D of
the inner plug 6C comes into contact with the corresponding
protrusion portion 32C and transfers a torque to the leading end
portion 32 of the shank 11. Then, each protrusion portion 32C
breaks from the wall surface 32b by the torque of the inner plug 6C
and the inner plug 6C rotates idly.
The maximum torque applied to the plurality of protrusion portions
32C in the process in which each protrusion portion 32C receives a
torque from the inner plug 6C and breaks from the wall surface 32b
and the inner plug 6C is placed in an idle rotation state is set to
be within a predetermined range. The predetermined range
corresponds to a desired fastening torque range. As a result, the
bolt 311 can be tightened to the fastened member 4 by a desired
fastening torque.
Each protrusion portion 32C forms a helical shape and each pressing
portion 6D of the inner plug 6C also forms a helical shape, and
hence the inner plug 6C can be prevented from falling out of the
hole 32a when the bolt 311 is fastened. As a result, the depth of
the hole 32a can be reduced, and hence the length of the bolt 311
can become shorter and the weight and the cost of the bolt 311 can
be reduced. The fastening torque can be changed by changing the
angle forming the helical shape of each protrusion portion 32C. The
bolt 311 having the abovementioned configuration achieves effects
similar to those in the bolt 301 of the fifth embodiment.
A bolt 321 according to the modification example 5-2 is described.
FIG. 24A is an explanatory view of a pintail 42 of the bolt 321
according to the modification example 5-2 and FIG. 24B is a
cross-sectional view of the bolt 321 and an inner socket 6E
according to the modification example 5-2 corresponding to the
cross-sectional view of the bolt 101 and the inner socket 3M taken
along the XII-XII line in FIG. 11.
In the bolt 321, the pintail 42 is provided on the leading end side
of the shank 11. The pintail 42 is inserted in the cylindrical
inner socket 6E when the bolt 321 is fastened. On an outer
peripheral surface 42A of the pintail 42, 12 outwardly projecting
protrusion portions 42B are provided. The protrusion portions 42B
are provided on the outer peripheral surface 42A of the pintail 42
at regular intervals in the circumferential direction of the
pintail 42. When the bolt 321 is fastened, each protrusion portion
42B receives a torque from each pressing portion 6F of the inner
socket 6E and breaks from the outer peripheral surface 42A. The
pintail 42 has 12 protrusion portions 42B and the inner socket 6E
has 12 pressing portions 6F, but only one protrusion portion 42B
and one pressing portion 6F are denoted by reference numbers in
FIG. 24A and FIG. 24B for simplification of illustration.
The inner socket 6E is rotated in the rotation direction R as
illustrated in FIG. 24B by the driving force from the driving
source (not shown) of the wrench 3 (FIG. 1) also in this
modification example. By this rotation, each pressing portion 6F of
the inner socket 6E comes into contact with the corresponding
protrusion portion 42B and transfers a torque to the pintail 42.
Then, each protrusion portion 42B breaks from the outer peripheral
surface 42A by the torque of the inner socket 6E and the inner
socket 6E rotates idly.
In the bolt 321, the maximum torque applied to the plurality of
protrusion portions 42B in the process in which each protrusion
portion 42B receives a torque from the inner socket 6E and breaks
from the outer peripheral surface 42A and the inner socket 6E is
placed in an idle rotation state is set to be within a
predetermined range. As a result, the bolt 321 can be tightened to
the fastened member 4 by a desired fastening torque.
The bolt 321 of this modification example achieves effects similar
to those in the bolt 301 according to the fifth embodiment.
Next, a bolt 331 according to the modification example 5-3 is
described. FIG. 25A is an explanatory view of a pintail 52 of the
bolt 331 according to the modification example 5-3 and FIG. 25B is
a cross-sectional view of the bolt 331 and an inner socket 6G
according to the modification example 5-3 corresponding to the
cross-sectional view of the bolt 101 and the inner socket 3M taken
along the XII-XII line in FIG. 11.
Eight outwardly projecting protrusion portions 52B are provided on
an outer peripheral surface 52A of the pintail 52 of the bolt 331
as illustrated in FIG. 25A and FIG. 25B. The protrusion portions
52B are provided on the outer peripheral surface 52A at regular
intervals in the circumferential direction thereof. The protrusion
portions 52B are helically provided along the axial direction of
the shank 11. That is, the axis (helical axis) forming a helical
shape of the protrusion portion 52B and the axis of the shank 11
are coaxially arranged. When the bolt 331 is fastened, each
protrusion portion 52B receives a torque from a pressing portion 6H
of the inner socket 6G and breaks from the outer peripheral surface
52A.
The inner socket 6G has eight pressing portions 6H. The pressing
portions 6H are helically provided so as to correspond to the
helical protrusion portions 52B. Eight protrusion portions 52B are
provided on the outer peripheral surface 52A and the inner socket
6G has eight pressing portions 6H, but only one protrusion portion
52B and one pressing portion 6H are denoted by reference numbers in
FIG. 25A and FIG. 25B for simplification of illustration.
The inner socket 6G is rotated in the rotation direction R as
illustrated in FIG. 25B by the driving force from the driving
source (not shown) of the wrench 3 (FIG. 1) also in this
modification example. By this rotation, each pressing portion 6H of
the inner socket 6G comes into contact with the corresponding
protrusion portion 52B and transfers a torque to the pintail 52.
Then, each protrusion portion 52B breaks from the outer peripheral
surface 52A by the torque of the inner socket 6G and the inner
socket 6G rotates idly.
In the bolt 331, the maximum torque applied to the plurality of
protrusion portions 52B in the process in which each protrusion
portion 52B receives a torque from the inner socket 6G and breaks
from the outer peripheral surface 52A and the inner socket 6G is
placed in an idle rotation state is set to be within a
predetermined range. As a result, the bolt 331 can be tightened to
the fastened member 4 by a desired fastening torque.
Each protrusion portion 52B forms a helical shape and each pressing
portion 6H of the inner socket 6G also forms a helical shape, and
hence the inner socket 6G can be prevented from falling out of the
pintail 52 when the bolt 331 is fastened. As a result, the length
of the pintail 52 can become shorter, and hence the length of the
bolt 331 can become shorter and the weight and the cost of the bolt
331 can be reduced. The fastening torque can be changed by changing
the angle forming a helical shape of the protrusion portion
52B.
The bolt 331 having the abovementioned configuration achieves
effects similar to those in the bolt 301 of the fifth embodiment.
In the fifth embodiment and the modification example 5-1, the
shapes of the holes 22a and 32a in the leading end portions 22 and
32 are linear shapes (substantially cylindrical shapes) along the
axis of the shank 11, but may be tapered shapes. In the same
manner, in the modification examples 5-2 and 5-3, the shapes of the
pintails 42 and 52 are linear shapes (substantially cylindrical
shapes) along the axis of the shank 11, but may be tapered shapes.
In the fifth embodiment and the modification example 5-1, each
length of the leading end portions 22 and 32 in the direction
orthogonal to the axis of the shank 11 may be shorter than the
diameter of the male screw portion 13 in the same manner as the
bolt 71 according to the modification example 1-6. As illustrated
in FIG. 26, a plurality of end surface protrusion portions 42D may
be provided on an end surface 42C of the pintail 42 of the bolt 321
and the plurality of end surface protrusion portions 42D may be
broken in addition to the plurality of protrusion portions 42B when
the bolt 321 fastened. As a result, the pintail 42 can become
shorter.
Next, a bolt 401 of a sixth embodiment of the present disclosure is
described with reference to FIG. 27A and FIG. 27B. The same parts
as those in the bolt 1 described in the first embodiment are
denoted by the same reference numbers and description thereof is
omitted. Only the different parts are described.
FIG. 27A is a cross-sectional view of a part near a leading end
portion 23 of the bolt 401 according to the sixth embodiment taken
along a plane including the shaft of the shank 11 and FIG. 27B is a
cross-sectional view of the bolt 401 and an inner plug 7A according
to the sixth embodiment corresponding to the cross-sectional view
of the bolt 1 and the inner socket 3A taken along the line in FIG.
1.
A hexalobular hole 23a is formed in the leading end portion 23 of
the shank 11 of the bolt 401. The inner plug 7A has a hexalobular
shape in correspondence to the hole 23a.
A wall portion 23B forming the hole 23a in the leading end portion
23 has six pressed portions 23C and six extension portions 23D.
When the bolt 401 is fastened, each pressed portion 23C receives a
torque from a pressing portion 7B of the inner plug 7A and is
pushed outward. Each extension portion 23D is plastically deformed
and extended by the torque from the inner plug 7A. The wall portion
23B forming the hole 23a has six pressed portions 23C and six
extension portions 23D and the inner plug 7A has six pressing
portions 7B, but only one pressed portion 23C, one extension
portion 23D, and one pressing portion 7B are denoted by reference
numbers in FIG. 27A and FIG. 27B for simplification of
illustration.
In this embodiment, the inner plug 7A and the outer socket 3B (FIG.
1) are rotated in directions opposite to each other by the driving
force from the driving source (not shown) of the wrench 3 (FIG. 1).
The inner plug 7A is rotated in the rotation direction R as
illustrated in FIG. 27B. By this rotation, each pressing portion 7B
of the inner plug 7A comes into contact with the corresponding
pressed portion 23C and transfers a torque to the leading end
portion 23 of the shank 11. Then, each pressed portion 23C is
pressed by the corresponding pressing portion 7B. Consequently,
each extension portion 23D is plastically deformed and extended,
each pressed portion 23C is extruded outward, the entire leading
end portion 23 is deformed so as to expand, and the inner plug 7A
rotates idly. As a result, the shape of the leading end portion 23
of the bolt 401 expands as illustrated in FIG. 28.
In the bolt 401, the maximum torque applied to the pressed portion
23C in the process in which each pressed portion 23C receives a
torque from the inner plug 7A and is extruded outward, the entire
shape of the leading end portion 23 expands in the direction
orthogonal to the axis of the shank 11, and the inner plug 7A is
placed in an idle rotation state is set to be within a
predetermined range. The predetermined range corresponds to a
desired fastening torque range. As a result, the bolt 401 can be
tightened to the fastened member 4 by a desired fastening torque.
The setting of the desired fastening torque in the bolt 401 can be
set as appropriate by adjusting the material of the bolt 401, the
depth of the hole 23a, the shapes of each pressed portion 23C and
each extension portion 23D, and the like.
The maximum length of the leading end portion 23 in the direction
orthogonal to the axis of the shank 11 after the expansion of the
shape of the leading end portion 23 is longer than the inner
diameter of the nut 2. Thus, according to the bolt 401 of this
embodiment, loosening and falling of the nut 2 can be prevented
after the bolt 401 is fastened. The bolt 401 of this embodiment has
a structure without a pintail, and hence the weight of the bolt 401
can be decreased and the cost can be reduced. In the bolt 401 of
this embodiment, no waste is generated and workability can be
enhanced.
Next, modification examples (modification examples 6-1 to 6-3) of
the bolt 401 according to the sixth embodiment are described. The
same parts as those in the bolt 401 according to the sixth
embodiment are denoted by the same reference numbers and
description thereof is omitted. Only the different parts are
described.
A bolt 411 according to the modification example 6-1 is described.
FIG. 29 is a cross-sectional view of the bolt 411 and an inner plug
7C according to the modification example 6-1 corresponding to the
cross-sectional view of the bolt 1 and the inner socket 3A taken
along the line in FIG. 1.
A hole 33a is formed in a leading end portion 33 of the shank 11 of
the bolt 411. A wall portion 33B forming the hole 33a in the
leading end portion 33 has two inwardly projecting pressed portions
33C and two extension portions 33D. Each pressed portion 33C
receives a torque from a pressing portion 7D of the inner plug 7C
and is pushed outward when the bolt 411 is fastened. Each extension
portion 33D is plastically deformed and extended by the torque from
the inner plug 7C.
The inner plug 7C is rotated in the rotation direction R as
illustrated in FIG. 29 by the driving force from the driving source
(not shown) of the wrench 3 (FIG. 1) also in this modification
example. By this rotation, each pressing portion 7D of the inner
plug 7C comes into contact with the corresponding pressed portion
33C and transfers a torque to the leading end portion 33 of the
shank 11. Then, each pressed portion 33C is pressed by each
pressing portion 7D. Consequently, each extension portion 33D is
plastically deformed and extended, each pressed portion 33C is
extruded outward, the entire leading end portion 33 is deformed so
as to expand, and the inner plug 7C rotates idly. As a result, a
part of the shape of the leading end portion 33 of the bolt 411
expands.
In the bolt 411, the maximum torque applied to the pressed portion
33C in the process in which each pressed portion 33C receives a
torque from the inner plug 7C and is extruded outward, a part of
the shape of the leading end portion 33 expands in the direction
orthogonal to the axis of the shank 11, and the inner plug 7C is
placed in an idle rotation state is set to be within a
predetermined range. As a result, the bolt 411 can be tightened to
the fastened member 4 by a desired fastening torque.
The bolt 411 of this modification example also achieves effects
similar to those in the bolt 401 of the sixth embodiment.
Next, a bolt 421 according to the modification example 6-2 is
described. FIG. 30 is a cross-sectional view of the bolt 421 and an
inner plug 7E according to the modification example 6-2
corresponding to the cross-sectional view of the bolt 1 and the
inner socket 3A taken along the line in FIG. 1.
A hexagonal hole 43a is formed in a leading end portion 43 of the
shank 11 of the bolt 421. A wall portion 43B forming the hole 43a
of the leading end portion 43 has six pressed portions 43C. Each
pressed portion 43C is located on the downstream side of each
corner portion of the hexagonal hole 43a in the rotation direction
R of the inner plug 7E. The inner plug 7E has a hexagonal cross
section and a pressing portion 7F that presses each pressed portion
43C. A groove 43e extending from an end surface of the leading end
portion 43 toward the head 12 side is formed in an outer peripheral
surface 43D of the leading end portion 43 at a location
corresponding to each corner portion of the hole 43a. The leading
end portion 43 has six pressed portions 43C and six grooves 43e and
the inner plug 7E has six pressing portions 7E, but only one
pressed portion 43C, one groove 43e, and one pressing portion 7F
are denoted by reference numbers in FIG. 30 for simplification of
illustration.
The inner plug 7E is rotated in the rotation direction R as
illustrated in FIG. 29 by the driving force from the driving source
(not shown) of the wrench 3 (FIG. 1) also in this modification
example. By this rotation, each pressing portion 7F of the inner
plug 7E comes into contact with the corresponding pressed portion
43C and transfers a torque to the leading end portion 43 of the
shank 11. Then, each pressed portion 43C is pressed by the
corresponding pressing portion 7F. Consequently, the leading end
portion 43 breaks along each groove 43e, each pressed portion 43C
is extruded outward, the entire leading end portion 43 is deformed
so as to expand, and the inner plug 7C rotates idly. As a result,
the shape of the leading end portion 43 of the bolt 421
expands.
The bolt 421 of this modification example also achieves effects
similar to those in the bolt 401 of the sixth embodiment.
Next, a bolt 431 according to the modification example 6-3 is
described. FIG. 31A is a view illustrating a leading end portion 53
of the bolt 431 according to the modification example 6-3 in a
state before fastening and FIG. 31B is a view illustrating the
leading end portion 53 of the bolt 431 according to the
modification example 6-3 in a state after fastening.
A hole 53a is formed in the leading end portion 53 of the shank 11
of the bolt 431. The screw portion 13 is not formed on the outer
periphery of the leading end portion 53. The maximum length of the
leading end portion 53 in the direction orthogonal to the axis of
the shank 11 after the expansion of the shape of the leading end
portion 53 is shorter than the inner diameter of the nut 2 as
illustrated in FIG. 31B. As a result, it is possible to easily
remove the nut 2 according to the bolt 431 according to this
modification example.
The above-mentioned embodiments of the present disclosure is merely
exemplified for description of the present disclosure and is not
intended to limit the scope of the present disclosure to only those
described in the embodiments. A person skilled in the art could
embody the present disclosure in other various modes without
departing from the gist of the present disclosure.
For example, in the bolt 1 of the first embodiment, an outer
peripheral surface 14B of the leading end portion 14 may have a
dodecagonal shape and may serve as a torque transfer portion that
receives a torque from a removal tool when the bolt 1 is removed as
illustrated in FIG. 32. As a result, the shape of the head 12 can
be simplified.
An additional pintail 86 serving as a torque transfer portion that
receives a torque from the removal tool when the bolt 101 is
removed may be provided on the leading end of the pintail 16 of the
bolt 101 of the third embodiment as illustrated in FIG. 33. As a
result, the shape of the head 12 can be simplified. When the bolt
101 is fastened, the pintail 86 may be used as a torque transfer
portion when the bolt 101 is removed and the pintail 16 may be used
as a torque transfer portion that receives a torque from the
removal tool.
* * * * *